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default	Fig | Fast, isolated development environments using Docker

Fast, isolated development environments using Docker.

Define your app's environment with Docker so it can be reproduced anywhere:

FROM orchardup/python:2.7
ADD . /code
RUN pip install -r requirements.txt
WORKDIR /code
CMD python app.py

Define the services that make up your app so they can be run together in an isolated environment:

web:
  build: .
  links:
   - db
  ports:
   - 8000:8000
db:
  image: orchardup/postgresql

(No more installing Postgres on your laptop!)

Then type fig up, and Fig will start and run your entire app:

There are commands to:

• start, stop and rebuild services
• view the status of running services
• tail running services' log output
• run a one-off command on a service

Fig is a project from Orchard. Follow us on Twitter to keep up to date with Fig and other Docker news.

Quick start

Let's get a basic Python web app running on Fig. It assumes a little knowledge of Python, but the concepts should be clear if you're not familiar with it.

First, install Docker. If you're on OS X, you can use docker-osx:

$ curl https://raw.github.com/noplay/docker-osx/master/docker-osx > /usr/local/bin/docker-osx
$ chmod +x /usr/local/bin/docker-osx
$ docker-osx shell

Docker has guides for Ubuntu and other platforms in their documentation.

Next, install Fig:

$ sudo pip install -U fig

(This command also upgrades Fig when we release a new version. If you don’t have pip installed, try brew install python or apt-get install python-pip.)

You'll want to make a directory for the project:

$ mkdir figtest
$ cd figtest

Inside this directory, create app.py, a simple web app that uses the Flask framework and increments a value in Redis:

from flask import Flask
from redis import Redis
import os
app = Flask(__name__)
redis = Redis(
    host=os.environ.get('FIGTEST_REDIS_1_PORT_6379_TCP_ADDR'),
    port=int(os.environ.get('FIGTEST_REDIS_1_PORT_6379_TCP_PORT'))
)

@app.route('/')
def hello():
    redis.incr('hits')
    return 'Hello World! I have been seen %s times.' % redis.get('hits')

if __name__ == "__main__":
    app.run(host="0.0.0.0", debug=True)

We define our Python dependencies in a file called requirements.txt:

flask
redis

And we define how to build this into a Docker image using a file called Dockerfile:

FROM stackbrew/ubuntu:13.10
RUN apt-get -qq update
RUN apt-get install -y python python-pip
ADD . /code
WORKDIR /code
RUN pip install -r requirements.txt
EXPOSE 5000
CMD python app.py

That tells Docker to create an image with Python and Flask installed on it, run the command python app.py, and open port 5000 (the port that Flask listens on).

We then define a set of services using fig.yml:

web:
  build: .
  ports:
   - 5000:5000
  volumes:
   - .:/code
  links:
   - redis
redis:
  image: orchardup/redis

This defines two services:

• web, which is built from Dockerfile in the current directory. It also says to forward the exposed port 5000 on the container to port 5000 on the host machine, connect up the Redis service, and mount the current directory inside the container so we can work on code without having to rebuild the image.
• redis, which uses the public image orchardup/redis.

Now if we run fig up, it'll pull a Redis image, build an image for our own code, and start everything up:

$ fig up
Pulling image orchardup/redis...
Building web...
Starting figtest_redis_1...
Starting figtest_web_1...
figtest_redis_1 | [8] 02 Jan 18:43:35.576 # Server started, Redis version 2.8.3
figtest_web_1 |  * Running on http://0.0.0.0:5000/

Open up http://localhost:5000 in your browser (or http://localdocker:5000 if you're using docker-osx) and you should see it running!

If you want to run your services in the background, you can pass the -d flag to fig up and use fig ps to see what is currently running:

$ fig up -d
Starting figtest_redis_1...
Starting figtest_web_1...
$ fig ps
        Name                 Command            State       Ports
-------------------------------------------------------------------
figtest_redis_1   /usr/local/bin/run         Up
figtest_web_1     /bin/sh -c python app.py   Up      5000->5000/tcp

fig run allows you to run one-off commands for your services. For example, to see what environment variables are available to the web service:

$ fig run web env

See fig --help other commands that are available.

If you started Fig with fig up -d, you'll probably want to stop your services once you've finished with them:

$ fig stop

That's more-or-less how Fig works. See the reference section below for full details on the commands, configuration file and environment variables. If you have any thoughts or suggestions, open an issue on GitHub or email us.